Hornets Vs Stessl

[fishfreak]

Any comments on who does a better hull for stability and riding? Both pretty much the same cost.......

Are the Mako boats still the same standard as that of the older Stessl make even though its from the same complany ?

Lets cast our votes on this one lads!!!!!!

[Bear]

I would probably look into the Mako more than the Stessl.

How would you determine either vessels stability?

There is such a thing as a "standard incline stability test" you know - but sadly boat builders have no onus to perform such tests when designing / manufacturing boats for recreational use.

That doesnt mean some of them don't design them to meet the test, and test the vessel after construction. Some also keep such records for later defence in a law suit situation where a life is lost in one of their vessels!

That said - theres nothing WRONG with you applying the test to ANY boats to determine the actual differences (if any).

Commercial boats that are put into survey actually have to pass such a test to gain a survey certificate.

To pass the test..

A vessel must be able to sustain a MINIMUM of 1/8th it's beam in clear freeboard, with ALL of it's rated passenger carrying capacity on ONE side at the same time!.

A passenger is I believe, an allowed weight of 74 kilo's ea.

So.

If the boat has a 8ft beam - and is rated for 4 people, THEN, with 296 kilos all on one gunnel...it must retain a clear 1 ft of freeboard.

So essentially, you can compare boats with nothing more than a few sand bags (or mates) some calm water and a tape measure!

Just make sure the boats "free floating" (not on the bottom) and that the ropes to the jetty have slack (i.e aren't holding it up in any way on the weighted side!) and measure from gunnel down to waterline when all 4 people are standing on the same side.

Now - having said that, how LOW in the boat you can store all your weight, will afffet it's stability.

What do you guys do in breaming boats? Yep raise everything up as high as you can get! (including the passengers!)

OK - try to keep heavey stuff like livewells and fuel tanks as LOW down in the hull as you can get.

There is something in boat design called a vessels 'metacentric height' and it's usually a position, somewhere between the "centre of bouyancy" COB...(weight of water displaced bouying the boat back UP) and it's "centre of gravity" COG, weight of vessel wanting to make it sink DOWN.

The vessel usually pivots side to side, about this "mystery" (metacentric height) point in stability terms.

The boats ability to "right itself" from a lean - is called it's "righting lever" and on a stability diagram would be called it's GZ curve.

The longer the righting lever - the more the boat has a long roll moment...(appears unstable) and the shorter the righting lever - the stiffer the roll moment appears (more stable).

When you put weight down BELOW the metacentric height - it helps shorten the righting lever and makes the boat more stable - and when you put all the weight up high, (above metacentric height) you get a less stable boat because you lengthen the righting lever (GZ).

So - when you rocket scientists are "rigging out your bare hulls" for breaming, the decisions you make about "where things should go" shouldn't be influenced by, what the idiot who posted a similar project before you did, because it gave him more room or whatever, the decision (from a safety and vessel handling point of view) should be about where it will help make the vessel more stable...and hence safe!

Basically - keeping the weight LOW in the hull is the answer.

eg,Question whats the BEST material for putting a "raised casting deck" in a boat - ply or ally sheet?

Which has the most weight? (Ply)

Is it above metacentric height? (Yes)

So, is ply the "best" material to use for a raised deck?

Answer = No (if you want a stable boat that doesn't rock like the old Rottnest Islander 11 until the portholes went underwater!).

Start to use your heads people, and start to get some "intelligent design" into your vessels.

Most of what I see I wouldn't take outside very smooth protected waters and it NEEDn't be like this...with a bit more thought into your designs IMHO.

Anyway - go measure a few vessel under real world conditions...

I defy a bream boat with raised decks and high water livewells, plastic above deck fuel tanks etc to retain 1/8th it's beam in clear freeboard with 4 people all standing on that raised deck on the one side at the same time...

If it CAN'T do it - then you SHOULDN'T be breaming in it IMHO - because - no one could get a dept transport survey on such a vessel to conduct for example bream tours...and if it aint safe for a paying passenger then it aint safe for you guys or the competition organisers with their public liability insurance either!.

Imagine as owner of vessel, and competition organiser - where a life has been lost in a comp!

Sorry insurance invalid - vessel modified by owner beyond original design intention and perameters, stability compromised, vessel owner at fault & competition organiser at fault for allowing unsafe vessel to enter comp.

Relatives lawyers sue vessel owner and comp organiser - NOT boat designer / manufacturer..

You guys Do realise what your messing with in all these breaming boat mods don't you?

Cheers!

[Alex]

Ford vs Holden